Transparent solar cell turns edge on and generates its own light

Enlarge / Solar panels sit on the roof of Google headquarters in Mountain View. (credit: Kimberly White/Corbis via Getty Images)

I love solar energy. Thanks to solar energy, on average, I’ve not had to pay for electricity for the last two years. Just because solar is already pretty good, though, doesn’t mean that it can’t be even cooler. Ladies and gentlemen, I give you transparent solar panels.

This area of research is addressing a couple of places where solar panels could be improved. For instance, it would be quite nice if we could coat windows with solar collectors but still let the light through. And, as a side effect, it may allow us to use each photon of light a little more efficiently. But how should we do that?

Using each photon twice

It turns out that these goals are connected. One of the ways that solar panels lose energy is when the photons have more energy than the solar cell can cope with.